This invention relates to a dust cover for covering the gap between a bore of a body member and a shaft rotatably received in the bore thereby preventing the gap from the ingress of dusts, water or the like.
Conventionally, a generally tubular member formed of flexible material such as rubber or the like constitutes the dust cover with one end being secured to the body member and the other end being secured to the outer circumference of the shaft. The intermediate portion connecting the opposite ends is formed to have a narrow width and covers the outer circumference of the shaft projecting out of the bore. In the conventional dust cover the sealing function is effected only by the intermediate portion, thus, there are shortcomings such that the intermediate portion will sometimes be damaged, particularly, when the dust cover is incorporated in a vehicle brake system or the like wherein foreign articles such as stones or the like will be picked up from the surface of a road in running the vehicle and will impact against the dust cover and that the operation of the shaft in the main body will be impaired by rusts and the wear owing to the breakage in the sealingness.